Zero mask fixtures for parts

ABSTRACT

Systems and methods are provided for securement of parts. One embodiment is a method for securing a part during fabrication. The method includes forming an interference fit between a pin and a wall defining a hole, supporting a weight of the part with the interference fit, and rotating the part around an axis of the part while the weight of the part is supported.

FIELD

The disclosure relates to the field of fabrication, and in particular,to tools for holding large parts in place.

BACKGROUND

Large parts, such as components of an airframe of an aircraft, may weighhundreds of pounds or more and may extend for tens or hundreds of feet.In order to perform work efficiently on such parts, the parts may besecured in place via one or more fixtures. However, fixtures for a largepart necessarily mask off affixed portions of the part from view. Thismeans that when a large part undergoes a surface treatment (e.g.,painting), the masked portions of the part do not receive the surfacetreatment. To address this problem, current techniques for surfacetreatment require a part to be secured to a fixture, treated, dried,moved to another fixture that couples with different locations on thepart, and then touched up. This is a highly labor-intensive process thatconsumes a great deal of time.

Therefore, it would be desirable to have a method and apparatus thattake into account at least some of the issues discussed above, as wellas other possible issues.

SUMMARY

Embodiments described herein provide for fixtures that secure a partwithout masking the surface of the part, by inserting pins of anadjustable diameter into holes within the part. Because the fixturessecure parts without masking the surfaces of those parts, the parts mayreceive surface treatments without the need for touch-up or re-mounting.In further embodiments, the fixtures facilitate rotation of a part aboutits center of mass, enabling technicians to freely reorient the part asneeded when applying a surface treatment. One embodiment is a method forsecuring a part during fabrication. The method includes forming aninterference fit between a pin and a wall defining a hole, supporting aweight of the part with the interference fit, and rotating the partaround an axis of the part while the weight of the part is supported.

A further embodiment is a non-transitory computer readable mediumembodying programmed instructions which, when executed by a processor,are operable for performing a method for fixing a part in place. Themethod includes aligning a pin with a hole in the part, inserting thepin into the hole, increasing a diameter of the pin to form aninterference fit with a wall defining the hole, supporting a weight ofthe part with the interference fit, and rotating the part around across-sectional center of mass of the part while the weight of the partis supported.

Another embodiment is a method of adapting a fixture for mounting a partto a track. The method includes applying an adapter to an end of abarrel pin that extends through a hole in a part and is in aninterference fit with side walls of the hole, placing the adapter onto atrack, and moving the part along the track by sliding the adapter withinthe track.

Yet another embodiment is a method of applying a surface treatment to apart. The method includes connecting side walls of a hole in a part to afixture, and applying a surface treatment to a surface of the part whilean interference fit connects the inner walls of the hole to the fixture.

A still further embodiment is an apparatus for supporting a part duringfabrication. The apparatus includes a fixture comprising a body, anengagement surface disposed along a length of the body, a slider thatengages with the groove and is configured to slide within the groove, ayoke having a first end affixed to the slider and having a securablesecond end, and at least one pin that protrudes away from the bodytowards the part, the pin forms an interference fit with a hole in thepart.

An additional embodiment is a method for securing a part duringfabrication. The method includes forming a connection between a pin at afixture and a hole at a part, supporting a weight of the part with theconnection, and rotating the part around an axis of the part while theweight of the part is supported.

Other illustrative embodiments (e.g., methods and computer-readablemedia relating to the foregoing embodiments) may be described below. Thefeatures, functions, and advantages that have been discussed can beachieved independently in various embodiments or may be combined in yetother embodiments further details of which can be seen with reference tothe following description and drawings.

DESCRIPTION OF THE DRAWINGS

Some embodiments of the present disclosure are now described, by way ofexample only, and with reference to the accompanying drawings. The samereference number represents the same element or the same type of elementon all drawings.

FIG. 1 illustrates a fixture in an illustrative embodiment.

FIG. 2 illustrates a fixation system comprising multiple fixtures in anillustrative embodiment.

FIG. 3 is a flowchart illustrating a method for applying a fixture to apart in an illustrative embodiment.

FIGS. 4-6 illustrate affixation of a pin to a part in an illustrativeembodiment.

FIGS. 7-8 illustrate rotation of a part and fixture about across-sectional center of mass of the part in an illustrativeembodiment.

FIG. 9 illustrates a barrel pin utilized by a fixture in an illustrativeembodiment.

FIGS. 10-11 are cut-through views illustrating motion of an internal rodthrough a barrel pin to cause an interference fit in an illustrativeembodiment.

FIG. 12 illustrates a fixture that includes a support in an illustrativeembodiment.

FIGS. 13-14 illustrate application of adapters to pins at fixtures inorder to facilitate moving a part via a track in an illustrativeembodiment.

FIG. 15 is a block diagram of a fixation system in an illustrativeembodiment.

FIG. 16 is a flowchart illustrating a method of adapting a fixture formounting a part to a track.

FIG. 17 is a flowchart illustrating a method of applying a surfacetreatment to a part.

FIG. 18 is a flow diagram of aircraft production and service methodologyin an illustrative embodiment.

FIG. 19 is a block diagram of an aircraft in an illustrative embodiment.

DESCRIPTION

The figures and the following description illustrate specificillustrative embodiments of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise variousarrangements that, although not explicitly described or shown herein,embody the principles of the disclosure and are included within thescope of the disclosure. Furthermore, any examples described herein areintended to aid in understanding the principles of the disclosure, andare to be construed as being without limitation to such specificallyrecited examples and conditions. As a result, the disclosure is notlimited to the specific embodiments or examples described below, but bythe claims and their equivalents.

FIG. 1 illustrates a fixture 100 in an illustrative embodiment. Fixture100 comprises any system, device, or component operable to securely holda large part in place by forming an interference fit with holes in thepart. The part may comprise a front spar, center spar, rear spar, or anycomponent for which a full surface treatment is desired. In thisembodiment, fixture 100 comprises body 110, which includes an engagementsurface (e.g., groove 112) disposed along a length of body 110 andflange 114 which follows the groove 112. Both body 110 and groove 112have an arcuate shape. Slider 120 is mounted within groove 112, slideswithin groove 112, and is supported by protrusions 132 of yoke 130. Yoke130 is itself supported by a fixed body (e.g., the ceiling, aground-based scaffold, etc.) via cable 134, and holds fixture 100 inplace. In one embodiment, a slider 120 is disposed within a groove 112on each side of fixture 100 and rolls/slides along flange 114.

Arms 140 (e.g., cantilevered arms) extend from body 110 of fixture 100,and may be adjustably positioned with respect to body 110 using mountingholes 142. By adjusting the mounting holes that are used to fixedlyattach an arm 140 to body 110, fixture 100 may be calibrated to supporta variety of part sizes and/or shapes. Pins 160 are affixed to arms 140via pin mount 150. Pins 160 protrude away from body 110 towards a part,and include a portion 162 (e.g., a portion of an axial length of a pin160) that increases in diameter to form an interference fit with a holein the part (e.g., as illustrated in FIGS. 9-11). In this embodiment,pin mount 150 is secured at two points 152, which in combination preventundesired pivoting. Meanwhile, arm 140 is fixed at the end whichcontacts body 110, in order to prevent pivoting.

Fixture 100 provides a technical benefit over prior fixation systemsbecause it utilizes pins 160 which have an adjustable diameter. Thisenables the pins to be inserted into holes at a part, and then expandedin size to form an interference fit with sidewalls of the hole. Theholes may comprise through-holes or blind holes. The holes may also bepositioned such that they extend toward a cross-sectional center ofgravity of the part being held. In this manner, the holes are orientedsuch that when a pin 160 is inserted, the pin may support the partwithout applying a torque to the part. In further embodiments, holes maybe disposed in locations where a neutral axis of the part will be thecenter of a cylinder formed by a radius of groove 112, such that thepart will hang without twisting or moving. The holes may even compriseundersized holes, and may be drilled out to an assembly diameter afterpins 160 at fixture 100 have been removed. When an interference fit isformed between fixture 100 and a part, the entire surface of the partremains visible and capable of receiving a surface treatment. Thus, theentire part may be surface treated without having to be re-mounted.Fixture 100 provides another technical benefit by allowing an affixedpart to be easily rotated by sliding slider 120. This may beaccomplished without having to release the part from fixture 100.

FIG. 2 is a diagram of a fixation system 250 comprising multiplefixtures 100 in an illustrative embodiment. According to FIG. 2,fixation system 250 holds a part 200 in place via multiple fixtures 100which hang from a fixed body 210 (e.g., a beam, a ceiling, etc.). Aheight of the part 200 may be controlled via pulley system 220, whichadjusts cabling for fixtures 100 in order to pull fixtures 100 up ordown. In some embodiments, pulley system 220 may even be adjusted toplace different one of fixtures 100 in different vertical locations.Part 200 includes a neutral axis 230. Centerlines 240 of holes in part200 (and therefore the axes of pins 160) intersect with neutral axis230. This means that after part 200 is rotated about its neutral axis230 while attached to fixtures 100, part 200 remains substantially atrest and does not experience substantial (e.g., any) resting torque torotate back to its original position. While neutral axis 230 isillustrated as forming a straight line, in further embodiments theneutral axis 230 may be curved or follow any suitable path. Pulleysystem 220 may also be adjusted to compensate for differences inelevation between fixtures 100 when securing a part having a curving orchanging neutral axis. Pulley system 220 may also be adjusted tocompensate for differences in elevation between fixtures 100 whensecuring a part having a curving or changing neutral axis.

While fixation system 250 is shown as including multiple fixtures 100 ofthe same design and size, in further embodiments the fixation system 250may use fixtures 100 of different shapes and/or sizes in order toaccommodate changes in the geometry of the part along the length of thepart.

Illustrative details of the operation of fixation system 250 will bediscussed with regard to FIG. 3. Assume, for this embodiment, that part200 is about to be mounted to a fixture 100 of fixation system 250.

FIG. 3 is a flowchart illustrating a method 300 for applying a fixtureto a part in an illustrative embodiment. The steps of method 300 aredescribed with reference to fixture 100 of FIG. 1, but those skilled inthe art will appreciate that method 300 may be performed with othersystems or devices. The steps of the flowcharts described herein are notall inclusive and may include other steps not shown. The steps describedherein may also be performed in an alternative order.

In step 302, a pin 160 is aligned with a hole in part 200. For example,as shown in FIG. 4, axis 420 of pin 160 may be made collinear withcenterline 240 of hole 400. After being aligned, pin 160 may slipbetween sidewalls 410 and into interior 402 of hole 400, because aportion 430 of pin 160 has a diameter (D1) that is less than a diameter(D2) of hole 400. Surfaces 450 of part 200 are also depicted in FIG. 4.

In step 304, at least one of pins 160 (e.g., one of pins 160, both pins160, etc.) is inserted into the hole 400. For example, the portion 430of pin 160 may be inserted within interior 402 of the hole 400 (asdepicted in FIG. 5). In step 306, a diameter of the pin 160 (e.g.,portion 430) is increased to form an interference fit between pin 160and a wall (i.e., sidewall 410) defining the hole 400 (as depicted inFIG. 6). This may comprise increasing the diameter of the portion 430until the diameter of the portion 430 meets or exceeds D2. This preventsthe part 200 from separating from pin 160, forming a secure fit. Theinterference fit also does not mask off surfaces 450. Surfaces 450therefore remain exposed to receive a surface treatment.

In further embodiments, hole 400 may include a lip or flange (not shown)that protrudes slightly out of the hole and partially covers a portionof surface 450. In such an embodiment, the portions that are covered bythe lip or flange may be drilled out when the hole 400 is drilled to afinal diameter for fabrication. This act of drilling out to the finaldiameter removes any masked areas. Such lips or flanges may help toprovide additional support to that provided by the interference fit withpin 160, or may replace an interference fit with a clamping fit.

In step 308, a weight of the part 200 is supported with the interferencefit. The part may then undergo a surface treatment while surfaces 450remain entirely exposed and the interference fit remains. In step 310,part 200 is rotated about its neutral axis 230 while the weight of thepart 200 is supported. This may be performed by sliding body 110 andgroove 112 around slider 120 as slider 120 remains supported by yoke130. Furthermore, this process ensures that part 200 remains at restafter it has been rotated, and does not experience any resting torque inits new position. This may facilitate easier access to surfaces 450during the surface treatment.

Method 300 provides a technical benefit by affixing large parts inmanner that does not mask off the surfaces of those parts. Method 300provides a further technical benefit by enabling large parts to beeasily rotated while they are secured to fixtures. This reduces theamount of labor involved in handling the part.

FIGS. 7-8 illustrate rotation of a part 200 and fixture 100 about across-sectional center of mass 750 of the part in an illustrativeembodiment. As shown in FIG. 7, part 200 is secured to fixture 100,which hangs from cable 720. Cable 720 is attached to cart 730, whichslides along fixed body 210 (e.g., a beam) into and out of the page.Part 200 is also illustrated as including one or more holes 710. Part200 is rotated in direction R2 about its cross-sectional center of mass750. which groove 112 of fixture 100 to slide along slider 120 indirection R1. In effect, rotation of part 200 may be accomplisheddirectly by rotating a fixture 100. In FIG. 8, part 200 has been rotatedto a new axial orientation. In this new orientation, different surfacesof part 200 may be more easily surface treated than before.

FIG. 8 also illustrates metal inserts 810 that may be inserted intoholes 710 within part 200. Metal inserts 810 may provide additionalstrength, particularly in embodiments where part 200 comprises acomposite part. Metal inserts 810 may for example be driven into acomposite part and may define the boundaries of a hole in the compositepart. In this particular embodiment, each metal insert 810 includes alip 812 that masks a small portion of the part. This masking may bedrilled out when hole 710 is drilled out from a tooling diameter to afinal diameter for fabrication.

FIG. 9-11 illustrate further details of the pins discussed above in anillustrative embodiment. Specifically, FIGS. 9-11 correspond with region9 of FIG. 1. FIG. 9 illustrates a barrel pin 900 utilized by a fixturein an illustrative embodiment. According to FIG. 9, barrel pin 900includes body 910, cylinder 920, and portion 930. portion 930 isconfigured to increase in diameter. An aperture 932 is included withinportion 930, and facilitates flexion of flanges 934. In this embodiment,barrel pin 900 may be covered by a sacrificial jacket 950. Sacrificialjacket 950 may form an outer surface of portion 930, and may comprise ahigh friction material or inexpensive sacrificial material (e.g., aplastic) that facilitates formation of an interference fit. Sacrificialjacket 950 may increase friction and gripping of a hole by barrel pin900 as well as protecting the portion of the pin under the sacrificialjacket 950. Sacrificial jacket 950 also receives a surface treatment(e.g., paint) instead of barrel pin 900, ensuring that barrel pin 900may be used again without degrading. In this embodiment, barrel pin 900includes a lip 940 which may or may not mask a small portion of asurface of a part, depending on the manner in which barrel pin 900 isinserted, the depth to which barrel pin 900 is inserted, and whether ornot a hole in the part is a through-hole or a blind hole. In embodimentswhere lip 940 provides masking, a diameter of the hole may be drilledout to eliminate the masking.

FIGS. 10-11 are cut-through views illustrating motion of an internal rodthrough a barrel pin to cause an interference fit in an illustrativeembodiment. In these illustrations, sacrificial jacket 950 has beeninstalled onto the barrel pin 900. Specifically, FIGS. 10-11 correspondwith view arrows 10 of FIG. 9. In FIG. 10, internal rod 1000 is drivenin direction Y (e.g., via a threaded screw drive) when it is turned indirection R3. This drives internal rod 1000 into an internal recess 1010defined by flanges 934. At this point, internal recess 1010 has adiameter of D2, which results in the barrel pin 900 having a diameterD1.

In FIG. 11, internal rod 1000, which has a diameter D3 greater than thediameter D2 of internal recess 1010, if further driven into internalrecess 1010. This generates forces F1 and F2 which cause the flanges 934to elastically deflect outward, increasing a diameter of the internalrecess to D4, resulting in a diameter of the portion 930 increasing toD5 which corresponds to a diameter of a hole. This may cause asacrificial jacket 950 placed over barrel pin 900 to contact a walldefining hole 400. If the sacrificial jacket 950 is damaged or deformedby holding the interference fit, it may be replaced before barrel pin900 is used to secure another part 200.

FIG. 12 illustrates a fixture 1200 that includes a support 1270 in anillustrative embodiment. Support 1270 is directly attached to a pin 1260in order to reinforce pin 1260. Backing 1272 of support 1270 is securedto body 1210. Meanwhile, spar 1274 and head 1276 of support 1270 provideadditional strength to support pin 1260 when pin 1260 is placed intoshear or experiences bending moments. This provides a technical benefitby reducing the chances of pin 1260 encountering plastic deformation orcracking.

FIGS. 13-14 illustrate application of adapters to pins at fixtures inorder to facilitate moving a part via a track in an illustrativeembodiment. In this embodiment, adapters 1310 and adapters 1320 areclamped, threaded, or otherwise affixed to pins of a fixture 100, afterthe pins have been secured to a part. Adapters 1310 include features1312 (e.g., grooves, wheels, balls) that facilitate sliding within atrack, and adapters 1320 include features 1322 which facilitate slidingwithin a track. In this manner, part 200 may be slid within a trackassembly without needing to be removed from fixtures 100. For example,as shown in FIG. 14, part 200 may be moved in directions 1400 withintrack assembly 1410, by using features 1312 and features 1322 as bearingsurfaces. In further embodiments, painting or other surface treatmentsmay be performed between step 308 and step 310 of method 300 above, andthe part may then be mounted to a track as illustrated in FIG. 13 andFIG. 14. One or more of fixtures 100 may be removed, or left on, duringthis process. In further embodiments, sacrificial jackets may be removedand/or replaced after painting.

In further embodiments, a part may be transferred from one set offixtures to another set of fixtures. In this embodiment, the weight ofthe part is supported via multiple pins that have been inserted intomultiple holes at the part, and the method for transfer includesreleasing a subset of the pins of a first fixture from a subset of theholes at the part, inserting a new set of pins of a second fixture intothe subset of the holes at the part, and releasing remaining pins of thefirst fixture. This method supports the part and enables access to anentire surface of the part without any resultant masking.

FIG. 16 is a flowchart illustrating a method of adapting a fixture formounting a part to a track. The method includes applying an adapter toan end of a barrel pin that extends through a hole in a part and is inan interference fit with side walls of the hole (step 1602), placing theadapter onto a track (step 1604), and moving the part along the track bysliding the adapter within the track (step 1606).

FIG. 17 is a flowchart illustrating a method of applying a surfacetreatment to a part. The method includes connecting side walls of a holein a part to a fixture (step 1702), and applying a surface treatment toa surface of the part while an interference fit connects the inner wallsof the hole to the fixture (step 1704).

EXAMPLES

In the following examples, additional processes, systems, and methodsare described in the context of a fixation system for a large part.

FIG. 15 is a block diagram of a fixture 1500 in an illustrativeembodiment. According to FIG. 15, fixture 1500 includes body 1510, whichdefines a groove 1512 in which a slider 1514 moves. A first end 1526 ofyoke 1520 is rotatably attached to slider 1514, and a second end 1524 ofyoke 1520 is attached to fixed body 1522. Arm 1530 extends from body1510, and includes mounting holes 1532 for adjusting its position. A pin1540 extends from arm 1530, and pin 1540 includes internal rod 1542,internal recess 1544, and flanges 1546. Pin 1540 is surrounded by asacrificial jacket 1548. Pin 1540 is inserted into hole 1552 within part1550. Hole 1552 is defined by a metal insert 1556 having walls 1554.

Pin 1540 may be expanded in diameter to form an interference fit withhole 1552, in order to support part 1550. Support 1560 providesadditional support to pin 1540 in order to enhance the strength of pin1540 in response to bending moments applied by part 1550. Metal insert1556 is optional and does not exist in all embodiments. Furthermore, itmay be possible to forego sacrificial jacket 1548 as well in someembodiments (e.g., when metal insert 1556 is used).

Referring more particularly to the drawings, embodiments of thedisclosure may be described in the context of aircraft manufacturing andservice in method 1800 as shown in FIG. 18 and an aircraft 1802 as shownin FIG. 19. During pre-production, method 1800 may include specificationand design 1804 of the aircraft 1802 and material procurement 1806.During production, component and subassembly manufacturing 1808 andsystem integration 1810 of the aircraft 1802 takes place. Thereafter,the aircraft 1802 may go through certification and delivery 1812 inorder to be placed in service 1814. While in service by a customer, theaircraft 1802 is scheduled for routine work in maintenance and service1816 (which may also include modification, reconfiguration,refurbishment, and so on). Apparatus and methods embodied herein may beemployed during any one or more suitable stages of the production andservice described in method 1800 (e.g., specification and design 1804,material procurement 1806, component and subassembly manufacturing 1808,system integration 1810, certification and delivery 1812, service 1814,maintenance and service 1816) and/or any suitable component of aircraft1802 (e.g., airframe 1818, systems 1820, interior 1822, propulsionsystem 1824, electrical system 1826, hydraulic system 1828,environmental 1830).

Each of the processes of method 1800 may be performed or carried out bya system integrator, a third party, and/or an operator (e.g., acustomer). For the purposes of this description, a system integrator mayinclude without limitation any number of aircraft manufacturers andmajor-system subcontractors; a third party may include withoutlimitation any number of vendors, subcontractors, and suppliers; and anoperator may be an airline, leasing company, military entity, serviceorganization, and so on.

As shown in FIG. 19, the aircraft 1802 produced by method 1800 mayinclude an airframe 1818 with a plurality of systems 1820 and aninterior 1822. Examples of systems 1820 include one or more of apropulsion system 1824, an electrical system 1826, a hydraulic system1828, and an environmental system 1830. Any number of other systems maybe included. Although an aerospace example is shown, the principles ofthe invention may be applied to other industries, such as the automotiveindustry.

As already mentioned above, apparatus and methods embodied herein may beemployed during any one or more of the stages of the production andservice described in method 1800. For example, components orsubassemblies corresponding to component and subassembly manufacturing1808 may be fabricated or manufactured in a manner similar to componentsor subassemblies produced while the aircraft 1802 is in service. Also,one or more apparatus embodiments, method embodiments, or a combinationthereof may be utilized during the subassembly manufacturing 1808 andsystem integration 1810, for example, by substantially expeditingassembly of or reducing the cost of an aircraft 1802. Similarly, one ormore of apparatus embodiments, method embodiments, or a combinationthereof may be utilized while the aircraft 1802 is in service, forexample and without limitation during the maintenance and service 1816.For example, the techniques and systems described herein may be used formaterial procurement 1806, component and subassembly manufacturing 1808,system integration 1810, service 1814, and/or maintenance and service1816, and/or may be used for airframe 1818 and/or interior 1822. Thesetechniques and systems may even be utilized for systems 1820, including,for example, propulsion system 1824, electrical system 1826, hydraulic1828, and/or environmental system 1830.

In one embodiment, a part comprises a portion of airframe 1818, and ismanufactured during component and subassembly manufacturing 1808. Thepart may then be assembled into an aircraft in system integration 1810,and then be utilized in service 1814 until wear renders the partunusable. Then, in maintenance and service 1816, the part may bediscarded and replaced with a newly manufactured part. Inventivecomponents and methods may be utilized throughout component andsubassembly manufacturing 1808 in order to manufacture new parts.

Any of the various control elements (e.g., electrical or electroniccomponents) shown in the figures or described herein may be implementedas hardware, a processor implementing software, a processor implementingfirmware, or some combination of these.

For example, an element may be implemented as dedicated hardware.Dedicated hardware elements may be referred to as “processors”,“controllers”, or some similar terminology. When provided by aprocessor, the functions may be provided by a single dedicatedprocessor, by a single shared processor, or by a plurality of individualprocessors, some of which may be shared. Moreover, explicit use of theterm “processor” or “controller” should not be construed to referexclusively to hardware capable of executing software, and mayimplicitly include, without limitation, digital signal processor (DSP)hardware, a network processor, application specific integrated circuit(ASIC) or other circuitry, field programmable gate array (FPGA), readonly memory (ROM) for storing software, random access memory (RAM),non-volatile storage, logic, or some other physical hardware componentor module.

Also, a control element may be implemented as instructions executable bya processor or a computer to perform the functions of the element. Someexamples of instructions are software, program code, and firmware. Theinstructions are operational when executed by the processor to directthe processor to perform the functions of the element. The instructionsmay be stored on storage devices that are readable by the processor.Some examples of the storage devices are digital or solid-statememories, magnetic storage media such as a magnetic disks and magnetictapes, hard drives, or optically readable digital data storage media.

Although specific embodiments are described herein, the scope of thedisclosure is not limited to those specific embodiments. The scope ofthe disclosure is defined by the following claims and any equivalentsthereof.

1. A method for securing a part during fabrication, the methodcomprising: forming an interference fit between a pin and a walldefining a hole; supporting a weight of the part with the interferencefit; and rotating the part around an axis of the part while the weightof the part is supported.
 2. The method of claim 1 wherein: rotating thepart comprises sliding a slider of a fixture along a groove of thefixture having an arcuate shape, wherein the slider is secured to afixed body and the pin is affixed to the fixture.
 3. The method of claim1 further comprising: increasing a diameter of the pin by: driving aninternal rod of the pin into an internal recess defined by flanges atthe pin, wherein the internal rod has a diameter that is greater than adiameter of the internal recess, causing the flanges to elasticallydeflect outward.
 4. The method of claim 1 further comprising: supportingthe pin with a support that that is directly attached to the pin andsecured to a fixture.
 5. The method of claim 1 further comprising:applying a surface treatment to a surface of the part while theinterference fit remains.
 6. The method of claim 1 further comprising:affixing the pin to a fixture via an arm; and adjustably positioning thearm with respect to a body of the fixture.
 7. The method of claim 1wherein: the pin is coupled with a fixture, and rotating the part isperformed by rotating the fixture.
 8. The method of claim 1 wherein:supporting the weight of the part is performed via multiple pins thathave been inserted into multiple holes at the part, and the methodfurther comprises: releasing a subset of the pins of a first fixturefrom a subset of the holes at the part; inserting a new set of pins of asecond fixture into the subset of the holes at the part; and releasingremaining pins of the first fixture.
 9. The method of claim 1 furthercomprising: increasing a diameter of the pin, which causes a sacrificialjacket forming an outer surface of the pin to contact the wall definingthe hole.
 10. The method of claim 1 further comprising: replacing asacrificial jacket at the pin after the interference fit has beenreleased.
 11. The method of claim 1 wherein: a centerline of the holeintersects a cross-sectional center of mass of the part. 12.-16.(canceled)
 17. A portion of an aircraft assembled according to themethod of claim
 1. 18. A non-transitory computer readable mediumembodying programmed instructions which, when executed by a processor,are operable for performing a method for fixing a part in place, themethod comprising: aligning a pin with a hole in the part; inserting thepin into the hole; increasing a diameter of the pin to form aninterference fit with a wall defining the hole; supporting a weight ofthe part with the interference fit; and rotating the part around across-sectional center of mass of the part while the weight of the partis supported.
 19. (canceled)
 20. A method of adapting a fixture formounting a part to a track, the method comprising: applying an adapterto an end of a barrel pin that extends through a hole in a part and isin an interference fit with side walls of the hole; placing the adapteronto a track; and moving the part along the track by sliding the adapterwithin the track.
 21. A method of applying a surface treatment to apart, the method comprising: connecting side walls of a hole in a partto a fixture; and applying a surface treatment to a surface of the partwhile an interference fit connects the inner walls of the hole to thefixture. 22-24. (canceled)
 25. An apparatus for supporting a part duringfabrication, the apparatus comprising: a fixture comprising: a body; anengagement surface disposed along a length of the body; a slider thatengages with an engagement surface and is configured to slide within theengagement surface; a yoke having a first end affixed to the slider andhaving a securable second end; and at least one pin that protrudes awayfrom the body towards the part, the pin forms an interference fit with ahole in the part.
 26. The apparatus of claim 25 wherein: the body has ashape that supports an ability to rotate the part.
 27. The apparatus ofclaim 25 wherein: the pin comprises: flanges that define an internalrecess; and an internal rod that has a diameter greater than a diameterof the internal recess, and that cause the flanges to elasticallydeflect when driven through the internal recess, increasing a diameterof the pin.
 28. The apparatus of claim 25 wherein: the pin is affixed toan arm that extends from the body.
 29. The apparatus of claim 25wherein: the pin further comprises a sacrificial jacket forming an outersurface of the pin.
 30. The apparatus of claim 25 further comprising: asupport that is directly attached to the body and is directly attachedto the pin in order to reinforce the pin.
 31. The apparatus of claim 25further comprising: an adapter that is secured to the pin andfacilitates sliding within a track assembly.
 32. Fabricating a portionof an aircraft using the apparatus of claim
 25. 33. A method forsecuring a part during fabrication, the method comprising: forming aconnection between a pin at a fixture and a hole at a part; supporting aweight of the part with the connection; and rotating the part around anaxis of the part while the weight of the part is supported. 34-35.(canceled)